Dear Statalisters,
I am trying to select a subpopulation for use with svy: mlogit.
The variable which specifies the subpopulation has 1130 observations
with a value of 1, 1792 0s and no missing data. However, when I run
the syntax (below), only 1099 observations are included in the analysis
xi: svy, subpop(varname): x y1 y2, rrr
Searching on the archives here brought me to a post about 'losing
observations'
"From Suzy <[email protected]>
To [email protected]
Subject st: Why does one command "lose" observations compared to
another command?
Date Sun, 22 Jan 2006 11:56:50 -0500 "
This problem seemed similar to the one I have and the answers
suggested that it might be something to do with a weights variable
having zeros on it.
I have checked my probability weight variable which is invoked earlier
in the syntax by svyset, and it contains 121 0s, which doesn't quite
explain the 131 missing observations.
When I specify the brr option to include both the probability weight
and bootstrap weights (see below), all 1130 observations ARE included
in the analysis
xi: svy brr, subpop(varname): x y1 y2, rrr
I would really appreciate any help.
Thanks,
Jamie
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